Improvement in lock-cutting machines



I. L. PEN N EY.

. Lock-Cutting Machines. No. 138,815. fatntedMayl3, l 873.

Witnesses .4 t1 orneys.

AM. PHOTU-LITHOGHAFHC ca My :seomsle moons?) UNITED STATES PATENT QFFIGE.

ISAAC L. PENNEY, OF MINNEAPOLIS, MINNESOTA.

IMPROVEMENT IN LOCK-CUTTING MACHINES.

Specification forming part of Letters Patent No. 138,815, dated May 13, 1873; application filed April 3, 1873.

To all whom it may concern:

Be it known that I, ISAAC L. PENNEY, of Minneapolis, in the county of Hennepin and in the State of Minnesota, have invented certain new and useful Improvements in Coopers Lock-Cutting Machine; and do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawing and to the letters of reference marked thereon making a part of this specification.

The nature of my invent-ion consists in the construction and arrangement of the devices, hereinafter described, for cutting locks in barrel-hoops, as will be set forth.

In the annexed drawing, A represents a wooden base, upon which is secured an iron frame, B. Upon one end of thisframe B is secured the knife (l, which is made of steel, as usual, and with a cutting-edge of peculiar shape, an outline of the same being seen in Fig. 2 from m to w. The face of the knife is roughened to hold more securely the hoop while the lock is being cut. D represents an arm, which is suitably hinged to the frame B at F. This arm is operated outward by means of a coiled or other spring. Upon the outer end of the arm D is a knife, E, which is curved upon its face, and has a square or rectangular oifset in it corresponding somewhat in shape with the knife 0. The knife E is secured to the arm D in such a position that when the said arm is carried downward the edges of the two knives pass each other as shears, making a shear-cut. The curve in the knife'E causes it to cut a concave face in the lock of the hoop, while its rectangular offset cuts a square shoulder, thus allowing the two ends of the hoop to meet and form a snug and secure lock.

The inclination and formation of the knives are such that the hoop while being cut is not forced away from the machine, or rather the cutting-edges, but is cut neatly, and that too very easily, with one downward stroke of the moving knife.

The arm D may be drawn or forced down by means of a rod or chain connected to its under side and passing to a suitable treadle.

Having thus fully described my invention, what I claim is-- The combination of the metallic frame B i with the angular knife 0 with cutting-edge,

as shown at w 00, secured upon one end. of the frame, and the inclined knife E attached to a bifurcated arm, D, hinged to a shaft at the other end of the frame, around which is coiled a spring, d, with one end projecting under the arm, all constructed and arranged substantially as and for the purposes herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 19th day of March, 1873.

ISAAC L. PENNEY. Witnesses:

VERNON BELL, H. O. HAMLIN. 

